Show device converts auto cylinder into air pump A new device that can be screwed into the sp spark ark plug hole of 0 one ot of the autos cylinders turns that cylinder into an air pump that will produce two and a halt half cubic feet ot of free air per minute this much air is sufficient to spray oil paint ge germicide mir insecticide and liquids says popular science monthly on on the down stroke of the piston in tile the cylinder to which the device Is fitted the piston sucks in outside air through a spring operated valve on the up stroke this valve closes and another opens all allowing the air to flow into a storage tank or into the pipe leading to the spray equipment it if more air Is needed than can be obtained from one cylinder in this way two of the devices can be used at tile the same time so as to double tho the output it la is designed to work at an engine speed equivalent to a road speed of 20 miles an hour ar |